This invention claims priority to the French Patent application serial number N 0008666 filed on Jul. 4, 2000.
The present invention relates to a window regulator for vehicle, comprising a guide rail presenting a slideway, a window-bearing slider in which is made a notch corresponding to the section of the slideway, to allow fit of said slideway and guiding of the slider in a direction parallel to the slideway, said notch being defined by walls of which the zones are in sliding abutment on the adjacent guiding faces of the slideway.
At the present time, the zones of abutment of the slider are constituted by planar surfaces in contact with the faces of the slideway. In order to promote slide, the faces of the slideway may be coated with grease or coated with a layer of an appropriate material having a low coefficient of friction with the material constituting the slider.
These arrangements give good results. However, it has been observed that the displacement of the slider along the rail causes noises, particularly in the case of vibration of the vehicle.
A more thorough study of the phenomenon revealed that such noises occur when there are specks of dust on the slideway. Now, it is inevitable that, in the long run, dust is deposited on the slideways.
WO 00 21766 relates to a window regulator having two guide rails bearing the window. In order to compensate the errors of parallelism between the two guide rails, one of the sliders is provided to be able to move in the longitudinal direction of the vehicle with respect to its guide rail. To that end, one flange of this guide rail, located in a longitudinal vertical plane, is inserted with a longitudinal clearance between two curvilinear walls of a notch made in this slider. This arrangement allows this slider to be guided in a longitudinal vertical plane, but does not allow guiding of this slider in a direction parallel to the slideway. It is therefore a xe2x80x9cslavexe2x80x9d slider, illustrated in FIG. 3 of this document, by opposition to a xe2x80x9cmasterxe2x80x9d slider, illustrated in FIG. 1 and forming the subject matter of the present invention.
It is an object of the present invention to eliminate the noises caused by the slider sliding along the slideway, even if the latter is covered with specks of dust.
The invention attains its object in that the zones of abutment of the slider are formed by regular convex surfaces with generatrix parallel to the direction of displacement of the slider.
Thus, thanks to the invention, the useful guiding surfaces are clearly reduced with respect to the state of the art.
The slider preferably presents only one zone of abutment opposite each guide wall of the slideway.
The slider is advantageously made of synthetic material and preferably polyoxymethylene.
The faces of the slideway are advantageously coated with a film of a material presenting a low coefficient of friction.